That friendship may be at once fond and lasting, there must not only be equal virtue on each part, but virtue of the same kind; not only the same end must be proposed, but the same means must be approved by both. We are often, by superficial accomplishments and accidental endearments, induced to love those whom we cannot esteem; we are sometimes, by great abilities, and incontestable evidences of virtue, compelled to esteem those whom we cannot love. But friendship, compounded of esteem and love, derives from one its tenderness, and its permanence from the other; and therefore requires not only that its candidates should gain the judgment, but that they should attract the affections; that they should not only be firm in the day of distress, but gay in the hour of jollity; not only useful in exigencies, but pleasing in familiar life; their presence should give cheerfulness as well as courage, and dispel alike the gloom of fear and of melancholy. To this mutual complacency is generally requisite an uniformity of opinions, at least of those active and conspicuous principles which discriminate parties in government, and sects in religion, and which every day operate more or less on the common business of life. For though great tenderness has, perhaps, been sometimes known to continue between men eminent in contrary factions; yet such friends are to be shewn rather as prodigies than examples, and it is no more proper to regulate our conduct by such instances, than to leap a precipice, because some have fallen from it and escaped with life. It cannot but be extremely difficult to preserve private kindness in the midst of publick opposition, in which will necessarily be involved a thousand incidents, extending their influence to conversation and privacy. Men engaged, by moral or religious motives, in contrary parties, will generally look with different eyes upon every man, and decide almost every question upon different principles. When such occasions of dispute happen, to comply is to betray our cause, and to maintain friendship by ceasing to deserve it; to be silent is to lose the happiness and dignity of independence, to live in perpetual constraint, and to desert, if not to betray: and who shall determine which of two friends shall yield, where neither believes himself mistaken, and both confess the importance of the question? What then remains but contradiction and debate? and from those what can be expected, but acrimony and vehemence, the insolence of triumph, the vexation of defeat, and, in time, a weariness of contest, and an extinction of benevolence? Exchange of endearments and intercourse of civility may continue, indeed, as boughs may for a while be verdant, when the root is wounded; but the poison of discord is infused, and though the countenance may preserve its smile, the heart is hardening and contracting.